Uterine Torsions

6/15/2013 7:00 AM

W ith our recent spike in temperature, I noticed our practice had an increase in emergency calls, particularly uterine torsions. A uterine torsion is a situation where the entire uterus rotates around effectively pinching off the exit (cervix) so the calf cannot be born on its own. The rotation can be to the left (counterclockwise) or to the right (clockwise), with the former being the more common. The typical call describes a cow that is due or overdue that is showing early signs of labor, such as holding the tail up, bagging up and being uncomfortable, yet does not really start full labor. If the client reaches into the uterus, they will typically say they cannot feel a calf, or they can only feel a hoof and the cow feels very tight or narrow.

I am always asked why these torsions occur and there is no one reason that has been proven as a cause, but we do know some associated factors that contribute. Uterine torsions are more common in the Brown Swiss, which may be due to the large size and deep abdomen of this breed allowing for uterine motion. Torsions are more common with male calves most likely due to the fact that bull calves move more than heifer calves and are slightly larger. The extra movement and body weight may get the uterus moving and allow it to flip over. Stressors to the cow are associated with this problem as well. Stresses can include overcrowding, and as we saw recently, heat stress. The calf feels what mom feels, and when mom is stressed, the calf responds with increased motion, which can rotate the uterus.

The next question is “When did the calf flip over?” There is no good answer for this question either. I have performed pregnancy exams on cows four months pregnant and found that the uterus was already flipped. I followed these cows and they proceeded to have a normal delivery. This may indicate that the calves may cause the uterus to rotate during pregnancy and then even flip back, but at some point, possibly when the calf is too big, the uterus cannot return to normal position.

Once a uterine torsion is suspected in a cow or heifer, you should call your veterinarian right away. With long delays in identifying the problem, complications and difficulties in delivering increase while calf viability starts to decline. In the next article, I will discuss the complications and post calving risks of this condition, how to try and determine if you have a case, and how your veterinarian may try to correct this type of dystocia.

Editor’s note: Stephen Foulke, DVM, DABVP (Dairy) is a board certified specialist in dairy practice with Agricultural Veterinary Associates in Lititz. He can be reached at 717-625-4212.